Rail bond terminal



Feb. 23,1943. E. .1. SABOL RAIFL BOND TERMINAL INVENTOR Ernesf J. Saba! Filed Feb. 25, 1942 Patented Feb. 23, 1943 UNITED STATES PATENT OFFICE Richard Wilson, and Theodore F. Wilson, Wilkinsburg, Pa., copartners trading as Hanlon &

Wilson Company Application February 25, 1942, Serial No. 432,233

3 Claims.

This invention relates generally to rail bond terminals and more particularly to that type of rail bond terminal which comprises an expansible stud portion adapted to be received in a rail cavity and expanded into engagement with the wall of the rail cavity.

As is well known, rail bonds are used for forming a part of the circuit in an electrical signaling system. The bond comprises an electrical conductor and a terminal at each end of the conductor. The two terminals are connected to adjacent ends of two rails by expanding the stud of the terminal into tight engagement with a cavity formed in each of the rails. This expansion of the stud is brought about by driving a pin into a bore in the terminal, a plug of soft material such as copper being located in the bottom of the bore and being expanded against the stud when the pin is driven into the bore. The expansion of the copper plug expands the stud of the terminal into engagement with the wall of the rail cavity.

It is an advantage in terminals of thetype to which the present invention relates to provide a terminal in which the plug of copper or other relatively soft material and the driving pin of relatively hard material are locked in the bore of the terminal when the terminal is manufactured but before the terminal is inserted into the rail cavity and secured thereto. In this way, the danger of losing either the copper plug or the driving pin is eliminated and the rail bond as delivered to the user has the copper plug and pin already secured in place in the terminal. It is then only necessary to insert the stud of the terminal into the rail cavity and to drive in the pin so as to expand the stud into engagement with the rail cavity.

The present invention also provides a rail bond terminal which after inserting the stud into the rail cavity and driving in the pin is securely locked to the rail, so that it will not become loosened due to the very severe vibrations to which it is subjected in use.

In the accompanying drawing, which illustrates several preferred embodiments of my invention,

Fig. 1 is a horizontal section through a portion of a railway rail and a portion of a rail bond illustrating the construction of the terminal. In this figure, the parts are shown in the positions which they assume after the driving pin has been driven to its final position and the stud of the terminal has been expanded into tight engagement with the rail cavity.

Fig. 2 is a vertical section through the terminal showing the pin and copper plug secured in the bore of the terminal in the course of manufacture of the terminal but before the terminal has been applied to a rail cavity and secured to the rail;

Figs. 3, 6 and 8 are vertical sections through different embodiments of terminals illustrating other ways in which the pin and copper plug may be secured in the bore of the terminal during the course of manufacture of the terminal and prior to its application to the rail;

Fig. 4 is a vertical section through a copper plug of the type illustrated in Fig. 3;

Fig. 5 is a front elevation of an expander element of the type used in Fig. 3; and

Fig. 7 is a vertical section through a hollow cylindrical copper plug of the type used in Fig. 6.

Referring now more particularly to the accompanying drawing, and for the present to Figs. 1 and 2, the rail 2 is provided with a cavity 3 in which the stud 4 of the terminal indicated generally by the reference numeral 5 is received. The stud is formed integrally with a head 6 of the terminal, which head is larger than the stud. The head isprovided with a sleeve 1 which encases an end 8 of the conductor which, as shown, is made up of a plurality of conducting wires. The sleeve 1 and conductor end 8 are made integral with the head 6 by electric welding. A bore 9 extends entirely through the head of the terminal and extends through a substantial portion of the stud 4. The inner end of the bore is closed by the end wall ID of the stud.

A hardened steel ball I I or a ball of other relatively hard material is located adjacent the inner end of the bore and when the parts are in the positions indicated in Fig. 1, in which the stud 4 has been driven into tight engagement with the rail cavity, the ball is embedded in a plug I2 of copper or other relatively soft material. Another hardened steel ball l3 or a ball of relatively hard material is located adjacent the top of the copper plug l2. A pin I 4 is locked in the bore of the terminal and in the position shown in Fig. 1 has been driven into the bore so that the bottom ill of thepin has driven the ball I 3 into the copper plug and expanded it. This expansion of the copper plug has expanded the stud 4 into tight engagement with the recess in the rail. The pin I4 is provided with a plurality of beads or collars I61: and l6b. The diameter of head [6a is slightly larger than the diameter of the bore 9 and the diameter of the bead l6b is slightly larger than the diameter of the bead l6a. When the pin is driven into the terminal, the bead Ilia slightly deforms the bore, forming the groove Fla. The bead l6b deforms the bore to a greater extent,

forming the groove llb and causing the metal of the bore to flow, thereby decreasing the cross section of the bore between the two beads and securely locking the pin in the terminal head.

In Fig. 2, the terminal is shown during its course of manufacture and prior to the time at which it is applied to the rail. In assembling the copper plug I2, the hardened steel balls II and I3 and the pin l4 in the terminal 6, the terminal is supported on a support or anvil l8 which is provided with an opening 19 which receives the stud 4. This opening is larger than the stud, so that the stud merely extends into the opening, the terminal being supported on the anvil by the shoulders 26. The ball H is first placed in the bottom of the bore and then the copper plug [2 is placed on top of the ball I I. It will be noted that the plug has a pocket 2i at each end which provides a seat for each of the balls II and [3. After the copper plug has been seated on the ball II, the ball l3 is placed in the upper pocket 2| and the pin I4 is inserted in the bore 9. The pin is driven into the bore to the position shown in Fig. 2, thereby locking the pin in the bore due to the provision of the beads Mia and lfib, but the pin is not driven into the bore far enough so that it expands the stud. With the parts in the position shown in Fig. 2, the pin and the copper plug and the hardened balls are all looked in the bore of the terminal and the terminal may be shipped in this condition to the user. The user then inserts the stud into the cavity in the rail and by driving the pin into the position shown in Fig. 1 expands the stud into tight engagement with the rail cavity.

It will be noted that in this embodiment a plurality of balls II and I3 or other equivalent expander elements are provided, one expander element being located adjacent the top of the copper plug and the other adjacent the bottom of the plug. When the pin is driven into final position as illustrated in Fig. l, the balls become embedded in the copper plug and due to the fact that a plurality of balls are provided, one adjacent the top and the other adjacent the bottom of the plug, the expansion pressure is exerted over substantially the entire area of the terminal stud. This forces substantially the entire area of the stud into very tight engagement with the wall of the rail cavity.

The embodiment illustrated in Fig. 3 is similar in principle to that illustrated in Fig. 2. In Fig. 3, an expander element 23 is used in place of the ball H of Fig. 2. This expander element 23 is generally pear-shaped and is positioned with its large end extending downwardly. A copper plug 24 or a plug of other relatively soft material is provided at its lower end with a tapered recess 25 which receives the upper end of the expander element 23. The driving pin 26 tapers upwardly and is locked in position in the bore of the terminal by first providing a cylindrical bore of a diameter sufficient to receive the large end of the pin, inserting the large end of the pin into the bore and then forcing the head of the terminal into contact with the pin by an upsetting operation. This upsetting operation is more specifically described in my co-pending application. Serial No. 434,883, filed March 16, 1942. In carrying out the upsetting operation, an upsetting tool is provided which has an opening which receives the upper end of the pin 26. The upsetting tool has an annular ring portion at its lower end which bites ino the terminal head forming the notch 21 and forces that portion of the head which lies adjacent the pin into tight engagement with the tapered pin.

The tapered pin 26 is provided adjacent its lower end with a conical shaped expander section 28 which penetrates into the copper plug 24 when the pin is driven into the terminal. In this modification, as in the embodiments shown in Figs. 1 and 2, pressure for expanding the stud into tight engagement with the wall of the rail cavity is provided by expander elements located adjacent the bottom of the copper plug and adjacent the top of the copper plug, so that the expansive forces are exerted uniformly over substantially the whole area of the stud.

In the embodiment illustrated in Figs. 6 and 7, the body 30 of the pin 3| is substantially cylindrical, it being neither tapered nor provided with enlarged portions such as the beads shown in Figs. 1 and 2. The lower end of the body of the pin is provided with an expander element 32 of less cross sectional area than the area of the body of the pin. This expander portion 32 is received in an opening 33 provided in a hollow cylindrical plug 34 of copper or other relatively soft material. The expander section 32 has a neck portion adjacent the bottom of the body 30 of the pin, so that when the pin is driven into the position shown in Fig. 6 the pin is locked to the copper plug and the copper plug is expanded sufficiently against the inner wall of the stud 4 so that both the copper plug and the pin are retained within the bore of the terminal. In this embodiment also after the parts have been assembled as shown in Fig. 6, the rail bond may be shipped to the user and the terminals applied to the recesses in the rails and the pin 31 driven to final position so as to expand the stud into tight engagement with the rail recess.

Referring to Fig. 8, the pin 40 is provided at its lower end with a tapped recess 4| which with the parts in the position shown in Fig. 8 is filled with a portion of the copper plug 42 which has been forced into the recess due to driving in the pin. When the parts are assembled and prior to driving the pin to the position shown in Fig. 8, the recess 4| is empty but upon driving in the pin the copper or other relatively soft material of the plug 42 is forced into the recess, thereby locking the pin 40 and plug 42 together. The pressure exerted by the pin also forces the copper plug into tight engagement with the inner wall of the stud 4 but does not expand the stud substantially. When it is desired to apply the terminal to a rail, the stud 4 is placed in the rail cavity and the pin is driven in further so as to expand the stud into tight engagement with the wall of the rail cavity.

It will be noted that in all of the embodiments the pin and copper plug are secured in the bore of the terminal, so that the terminal may be shipped to the user without fear of loss of either the pin or the copper plug. In the embodiment illustrated in Fig. 2, the pin is locked in the terminal head by the beads lfia and H61), whereas in Fig. 3 the pin is locked in the head by upsetting the terminal head against the pin. In the embodiments illustrated in Figs. 6 and 8, the copper plug and the pin are locked to each other and, since the plug has been expanded into tight engagement with the inner wall of the stud 4, both the copper plug and the pin are retained in the bore of the terminal.

While I have illustrated and described certain preferred embodiments of the invention, it is to be understood that the invention may be otherwise embodied or practiced within the scope of the following claims:

I claim:

1. A rail bond terminal comprising a head, an expansible stud adapted to be received in a rail cavity, a bore extending through the head and through a substantial portion of the length of the stud, one end of the bore being closed by the end wall of the stud, a relatively soft material in the bore of the stud, a pin of relatively hard material locked in the bore, and a plurality of expander elements of relatively hard material, one of said expander elements located adjacent the top of said soft material and another of said expander elements located adjacent the bottom of said soft material.

2. A rail bond terminal comprising a head, an expansi'ole stud adapted to be received in a rail cavity, a bore extending through the head and through a substantial portion of the length of I the stud, one end of the bore being closed by the end wall of the stud, a relatively soft material in the bore of the stud, a pin of relatively hard material locked in the bore, and a plurality of balls of relatively hard material, one of said balls located adjacent the top of said soft material and another of said balls located adjacent the bottom of said soft material.

3. A rail bond terminal comprising a head, an expansible stud adapted to be received in a rail cavity, a bore extending through the head and through a substantial portion of the length of the stud, one end of the bore being closed by the end wall of the stud, a relatively soft material in the bore of the stud, a pin of relatively hard material locked in the bore, and a plurality of expander elements of relatively hard material, one of said expander elements located adjacent the bottom of said relatively soft material, another of said expander elements located adjacent the top of said relatively soft material and formed integrally with said pin.

ERNEST J. SABOL. 

